Investigation of Flow Physics of Vane Clocking Effects on Rotor Resonant Response

Vane clocking is the circumferential indexing of adjacent vane rows with identical vane counts. Vane clocking affects tone noise propagation, performance, and forced response characteristics in compressors. Recent vane clocking experiments performed in the embedded stage of the Purdue 3-Stage Research Compressor showed significant differences in the rotor 2 resonant response depending on the clocking configuration of stator 1 and stator 2, as measured by a nonintrusive stress measurement system. This research is focused on computing the fluid-structure interaction observed in this experiment to gain further insight into the flow physics associated with vane clocking. AU3D, an implicit, unsteady, unstructured, compressible flow solver is used to compute the vane clocking effects on rotor 2 resonant response, and the results are compared with experimental data. While many have investigated vane clocking effects on unsteady blade loading, this is one of the few investigations focused on rotor resonance.